A ceramic honeycomb body, suitable for use in exhaust gas processing, includes a honeycomb structure having a plurality of through-channels, a first portion of the plurality of through-channels have a first hydraulic diameter dh1, a second portion of the plurality of through-channels have a second hydraulic diameter that is smaller than the first hydraulic diameter dh1, the first hydraulic diameter dh1 is equal to or greater than 1.1 mm, and the first and second portions of through-channels, taken together, have a geometric surface area GSA greater than 2.9 mm.sup.−1. Diesel oxidation catalysts and methods of soot removal are also provided, as are other aspects.

A plugged honeycomb structure, including: a pillar-shaped honeycomb structure body including porous partition walls; and plugging portions disposed at open ends of cells at an inflow end face side or at an outflow end face side, wherein a pore diameter corresponding to the cumulative pore volume of 10% is D10, a pore diameter corresponding to the cumulative pore volume of 30% is D30, a pore diameter corresponding to the cumulative pore volume of 50% is D50, a pore diameter corresponding to the cumulative pore volume of 70% is D70, a pore diameter corresponding to the cumulative pore volume of 90% is D90, the pore diameter D10 is 6 μm or more, the pore diameter D90 is 58 μm or less, and the plugged honeycomb structure satisfies the relationship of Expression (1).
0.35≤(D70−D30)/D50≤1.5  Expression (1):

A method for drying at least one unfired columnar honeycomb formed body comprising a raw material composition containing at least one raw material of ceramics, water and at least one heat-gelling binder, and cells defined by partition walls comprising flow paths from a first end surface to a second end surface. The method comprising drying the honeycomb formed body by passing hot gas satisfying 0.8≤T2/T1≤3.3, where T1 represents a gelation temperature of the binder (° C.) and T2 represents a wet-bulb temperature of the hot gas (° C.) through the flow paths from the first end surface and out the second end surface, while surrounding the honeycomb formed body with a correction mold to correct the shape of the honeycomb formed body during drying.

A honeycomb body having intersecting porous walls which includes first through fourth cells, wherein the cells extend from inlet to outlet face and are plugged to define a repeating structural unit with three inlets and one outlet channel. Repeating structural unit includes a first channel including length L.sub.1, width W.sub.2, and area A.sub.1, a second channel including length L.sub.2, the width W.sub.2, and area A.sub.2, a third channel including the length L.sub.1, width W.sub.1, and area A.sub.3, and a fourth channel including the length L.sub.2, the width W.sub.1, and A.sub.4, wherein the first through third channels are inlets and the fourth channel is a rectangular outlet and at least one of W.sub.1≥W.sub.2 and L.sub.1≠L.sub.2, i.e. W.sub.1≥W.sub.2, or L.sub.1≠L.sub.2, or W.sub.1≥W.sub.2 and L.sub.1≠L.sub.2. Repeating structural unit has a quadrilateral outer perimeter. Particulate filters including the honeycomb body, honeycomb extrusion dies, and methods of manufacturing the honeycomb body are provided.

A honeycomb filter includes a pillar-shaped honeycomb structure body having a porous partition wall disposed to surround a plurality of cells and a plugging portion. The partition wall defining outflow cells includes an exhaust-gas purifying catalyst at least at a part of a region of 0 to 80% of a thickness of the partition wall and includes a portion that does not include the exhaust-gas purifying catalyst in a region of exceeding 80% and being 100% or less of the thickness of the partition wall, and the partition wall defining the inflow cells is not loaded with the exhaust-gas purifying catalyst on the surface, or is loaded with the exhaust-gas purifying catalyst so that a percentage of a ratio of an area of a range loaded with the exhaust-gas purifying catalyst to a surface area of the partition wall defining the inflow cells is 10% or less.

A honeycomb filter includes: a honeycomb structure having porous partition walls disposed so as to surround cells, and plugging portions disposed at any one of ends on the inflow end face and the ends on the outflow end face, of cells. In a cross section perpendicular to an extending direction of the cells, a thickness T1 of the partition walls in a central portion including a center of gravity O of the cross section is 0.17 to 0.32 mm, a thickness T2 of the partition walls in an outer peripheral portion is 70 to 90% of the thickness T1, and the outer peripheral portion extends from an outer peripheral edge of the cross section of honeycomb structure by 6 to 12% of a radius r which is from the center of gravity O of the cross section to the outer peripheral edge.

A honeycomb filter includes a honeycomb structure body that has porous partition walls disposed so as to surround cells, and plugging portions that are disposed at any one of the ends on the inflow end face and the ends on the outflow end face. A cross-sectional shape of each of the inflow cells is octagonal and a cross-sectional shape of each of the outflow cells is quadrangular. An area ratio (S1/S2) of a cross-sectional area S2 of each of the outflow cells to a cross-sectional area S1 of each of the inflow cells is 1.40 to 2.20. The plugging portions have convex portions that protrude from the end faces on which the plugging portions are disposed, toward the outer sides, and have a protruding height H of 0.3 to 3.0 mm, and the plugging portions have a plugging depth L of 4.0 to 9.0 mm.

A honeycomb filter comprising a pillar-shaped honeycomb structure body having a porous partition wall and a plugging portion, wherein a thickness of the partition wall is 0.217 mm or less, a porosity of the partition wall is 57 to 63%, an average pore diameter of the partition wall is 6 to 14 μm, a number per unit area of pores which exist at a surface of the partition wall and which have equivalent circle opening diameters exceeding 3 μm is 800 to 1500 /mm.sup.2, an average equivalent circle opening diameter of pores which exist at a surface of the partition wall and which have equivalent circle opening diameters exceeding 3 μm is 6.7 to 12.5 μm, and in a pore diameter distribution of the partition wall, D10 is 3.0 to 7.0 μm, D90 is 13.0 to 27.0 μm, and (Log (D90)-Log (D10))/Log (D50) is 0.75 or less.

A particulate filter having a honeycomb structure of a matrix of interconnected porous walls including inlet cells and outlet cells defining a plurality of inlet channels and outlet channels, respectively, wherein at least a portion of the outlet cells are larger than any of the inlet cells, and a cross-sectional shape of at least some of the outlet channels is rectangular. Honeycomb extrusion dies, honeycomb bodies, honeycomb structures, and methods of manufacture are described, as are other aspects.

Disclosed herein are filtration articles comprising a porous ceramic structure comprising a plurality of channels separated by a plurality of porous interior walls, and a nanomembrane disposed on at least a portion of a surface of the porous ceramic structure, wherein the nanomembrane comprises nanoparticles of at least one inorganic oxide, and wherein the nanoparticles are present in a concentration ranging from about 0.001 g/L to about 1 g/L based on the total volume of the porous ceramic structure. Methods for making such filtration articles and methods for filtering a particulate from a fluid using such filtration articles are also disclosed herein.